Such reaction products as well as their use for the improvement of fastness properties of dyeings with substantive dyestuffs have long been known. Thus DE-A-855 001 describes polycondensates obtained by heating a polyfunctional amine with cyanamide or a polymer or a derivative thereof in the absence of water, optionally in the presence of non-aqueous solvents, under elimination of ammonia. According to EP-A-0 431 423 these products contain, due to the process by which they are produced, water-insoluble by-products, a drawback which can be eliminated by carrying out the condensation between the polyfunctional amine and the cyanamide or its derivative or polymer in the presence of ammonium salts, such as ammonium chloride, sulfate, carbonate, formiate or acetate, in the absence or presence of a non-aqueous solvent, preferably in the presence of a solvent containing hydroxy groups and having a boiling point above 180.degree. C. According to EP-A-0 692 511 an advantageous modification of this process consists of reacting the polyfunctional amine with the ammonium salt in the presence of a non-aqueous solvent and heating the protonised product thus obtained with the cyanamide component; this embodiment improves the safety of the process.
JP-A-60 252 787 describes wet fastness boosters for cellulose fiber dyed material, comprising the product of a polycondensation of an aliphatic diamine having 6 or more carbon atoms, preferably 1,6-hexanediamine or 2,2,4-trimethylhexamethylenediamine, or a salt thereof with an inorganic acid or an organic acid (such as formic, acetic and sulfamic acid), preferably the hydrochloride, with a guanidine compound or a salt thereof, preferably dicyandiamide, guanidine hydrochloride or guanidine sulfate. The resulting polycondensates are stated to have improved fastness-providing properties as compared with similar products obtained from other diamines.